using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Please input a text with a *");

        string text =Console.ReadLine();

        Console.WriteLine("Hello World");

        newtext (text);

    }

    public static void newtext (string text){

        int h=0;

        bool isunicode=false;

        string textg="";

        bool failmax=true;

        bool maxh= false; 

        int i=0;

        while (isunicode == false&&h< text.Length){

            isunicode =Char.IsLetterOrDigit(text,h );

            h++;

            if( text.Substring(0,h).Equals("*") ){

                isunicode = true;

            }

        }

        if ( text.Contains("*")&& isunicode == true){

            string texth =Console.ReadLine();

            Console.WriteLine(textg );

            while(i<= text.Length||failmax== true){

                if (text.Substring(0,i).Contains("*")&&failmax== true){

                    text=text.Substring(0,i).Replace("*", texth);

                    maxh=true;

                    }

                if (maxh==true&&i<= text.Length){

                            failmax= Char.IsLetterOrDigit(text,i );

                    Console.WriteLine(failmax);

                }

                i++;

            }

            Console.WriteLine(textg );

            Console.WriteLine(text);

        }

        else {

            Console.WriteLine("Error");

        }

        if (failmax== false || isunicode ==false){

            Console.WriteLine("Invalid characters");

        }

    }

}